1. Field of the Invention
The present invention relates to an image reading apparatus which reads an image on an original.
2. Description of the Related Art
Conventionally, an image forming apparatus such as a digital copying machine is adapted to discharge an original on a fed original stacking portion to an original discharge portion provided below the fed original stacking portion via an original reading portion. Such operation is performed by an automatic original feeding apparatus (hereinafter referred to as an “ADF (Auto Document Feeder)”) included in the image forming apparatus.
In the image forming apparatus, the original is conveyed from the fed original stacking portion to the original discharge portion by the ADF and removed from the original discharge portion by a user. There is a problem, however, that the area around the original discharge portion is darkened by the fed original stacking portion provided above the original discharge portion, thereby causing poor visibility of the original that is discharged. There is another problem that an original for a previous user and an original for a next user get mixed up on the original discharge portion when the previous user forgets to remove the original without noticing the discharged original.
As a method to improve the visibility of the original discharged to the original discharge portion, Japanese Patent Laid-Open No. 08-339107 discloses a sheet discharge tray provided between an image reading portion on the upper part of the apparatus and an image forming portion on the lower part of the apparatus. Also, it is suggested that an illumination lamp to illuminate inside the sheet discharge tray and improve the visibility of a recording sheet which is discharged onto the sheet discharge tray after recording has been performed onto the sheet by a copying operation or receiving a facsimile.
Moreover, Japanese Patent Laid-Open No. 2008-10902 discloses providing a lighting which illuminates the original discharge portion of the image reading portion, and providing a see-through portion which is on the fed original stacking portion and through which the original discharge portion can be seen. Also, an original detecting portion which detects the original that is discharged is provided. The lighting for illuminating the original discharge portion is provided. The lighting illuminates the original discharge portion when the original has been on the original discharge portion for a certain period of time. This can thus prevent the case where the user forgets to remove the original from the original discharge portion. Moreover, the lighting is turned off after a predetermined time elapses (such as after about 10 seconds) since the start of the illumination for saving electricity.
According to Japanese Patent Laid-Open No. 08-339107, however, the illumination light from the illumination lamp is intercepted by the sheet being discharged during the discharge operation for the sheet and thus does not reach the sheet discharge tray. Furthermore, when a number of sheets are stacked, a distance between the uppermost sheet of the stack and the illumination lamp is decreased to cause the range of illumination by the illumination lamp to shrink. Thus, it may be difficult to visually recognize the illumination light on the stacked sheet from outside.
According to Japanese Patent Laid-Open No. 2008-10902, the lighting is provided in the vicinity of the see-through portion provided on the fed original stacking portion, whereby the original discharged to the original discharge portion and illuminated by the illumination light can be visually recognized through the see-through portion when there is no original on the fed original stacking portion. When an original is on the fed original stacking portion, however, the illumination light onto the original stacked on the original discharge portion cannot be visually recognized through the see-through portion because the original blocks the see-through portion.
It tends to be difficult particularly in the image reading apparatus to visually recognize the illumination due to the narrow interval between the fed original stacking portion and the original discharge portion. The range of illumination by the illumination light also shrinks when the large amount of originals are stacked on the original discharge portion since the distance between the uppermost original of the stack and the lighting is decreased, thereby making it difficult to visually recognize the illumination light onto the stacked original. The same problem occurs in Japanese Patent Laid-Open No. 08-339107. Therefore, the visibility of the original discharge portion is reduced when the large amount of originals are stacked as compared to when the small amount of originals are stacked.
In the present invention that solves the aforementioned problems, it is desired that an image reading apparatus is provided in which the illuminated state of an original discharge portion does not vary much between during and after original discharge operation, or does not vary much regardless of the amount of originals stacked on the original discharge portion. It is further desired that an image reading apparatus is provided in which the effect of notifying an user to not forget to take out an original can be stably obtained.